In a particular class of air filter apparatus, commonly referred to as dust collector systems, it is known to utilize a reverse pulse of compressed air to clean contaminants which have accumulated on the filter medium. It has also been known to utilize various arrangements, such as venturi sections, to enhance the flow of the reverse stream for pressurization of the interior of the filter assemblies in the cleansing operation. Examples of some prior art, arrangements of this type can be found in U.S. Pat. Nos. 3,436,899, 3,499,268, 3,538,687 and 3,798,878.
Among the general objects of this invention are to improve the overall effectiveness of such filter arrangements. A more specific objective is to increase the efficiency of the reverse pulse stream and thereby improve the effectiveness of the overall filter medium cleaning.